PUBLICATION

Mitigative effects of natural and model dissolved organic matter with different functionalities on the toxicity of methylmercury in embryonic zebrafish

Authors
Li, D., Xie, L., Carvan, M.J., Guo, L.
ID
ZDB-PUB-190612-9
Date
2019
Source
Environmental pollution (Barking, Essex : 1987)   252: 616-626 (Journal)
Registered Authors
Carvan III, Michael J.
Keywords
Dissolved organic matter, Embryonic zebrafish, Methylmercury toxicity, Mitigative effect, Natural organic matter
MeSH Terms
  • Animals
  • Embryo, Nonmammalian
  • Humic Substances/analysis
  • Methylmercury Compounds/chemistry
  • Methylmercury Compounds/toxicity*
  • Mississippi
  • Rivers
  • Salicylates
  • Sulfhydryl Compounds/chemistry
  • Water Pollutants, Chemical/analysis
  • Water Pollutants, Chemical/toxicity*
  • Zebrafish/embryology*
PubMed
31185350 Full text @ Environ. Pollut.
Abstract
Dissolved organic matter (DOM) occurs ubiquitously in aquatic environments and plays an intrinsic role in altering the chemical speciation and toxicity of methylmercury (MeHg). However, interactions between MeHg and natural DOM remain poorly understood, especially at the functional group level. We report here the mitigative effects of three natural organic matter (NOM) and five model-DOM under different concentrations (0, 1, 3, 10, 30 and 100 mg-C/L) on the toxicity of MeHg in embryonic zebrafish (<4 h post-fertilization, hpf). NOM are those from the Mississippi River, Yukon River, and Suwannee River, while model-DOM include those containing thiosalicylic acid, L-glutathione, dextran, alginic acid, and humic acid. We selected a MeHg concentration (100 n-mol/L) that reduces the survival rate of embryos at 24 hpf by 18% and increases malformations at 72 and 96 hpf. In the presence of DOM, however, the malformation rates induced by MeHg can be mitigated to a different extent depending on DOM concentrations, specific functional groups, and/or specific components. Model DOM with aromatic thiols was the most effective at mitigating the effects of MeHg, followed by L-glutathione, carbohydrates, and humic acid. NOM also mitigated the toxicity of MeHg dependent on their composition and/or effective DOM components as characterized by fluorescence excitation-emission matrix techniques. Specifically, humic-like DOM components are more effective in reducing the MeHg toxicity in the embryonic zebrafish compared to protein-like components. Further studies are needed to elucidate the interactions between DOM and MeHg and the mitigative mechanisms at the molecular level.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping